University study finds source of algal blooms in Lake Erie

Sunday, November 25, 2018 - 8:04pm

The team identified cyanobacteria cells as the culprit for summer blooms, surviving at the bottom of the lake during the winter and reemerging in the spring.

The team identified cyanobacteria cells as the culprit for summer blooms, surviving at the bottom of the lake during the winter and reemerging in the spring. Buy this photo
Mike Zlonkevicz/Daily

Under the surface of Lake Erie lies a vast and complex ecosystem of plants and animals. In a recent study, University of Michigan scientists dove into the biology of the lake’s algae population to better understand the catalyst of their summer blooms and the potential hazards they pose to the environment.

According to a University press release, the study — conducted by the University’s Cooperative Institute for Great Lakes Research — found cyanobacteria cells to be the cause of Lake Erie’s summer algal blooms. Over two years, researchers evaluated the sediment-core of 16 sites up to 30 feet deep over 145 square miles in the lake’s western area, as it has been greatly affected by the blooms.

The team identified cyanobacteria cells as the culprit for summer blooms, surviving at the bottom of the lake during the winter and reemerging in the spring. Christine Kitchens led the study for her master’s thesis and highlighted the environmental implications of the research. She deemed the cyanobacteria behavior as “seeding” the algal bloom, which explains the increase in size and extent of the blooms in early summer.

“The study suggests that the initial buildup of blooms can happen at a much higher rate and over a larger spatial extent than would otherwise be possible, due to the broad presence of viable cells in sediments throughout the lake,” Kitchens said in the release. “These overwintering cells can quickly be entrained within the water column — particularly after a storm event — and start actively growing.”

Lake Erie algal blooms are caused by cyanobacteria which can produce microcystins, a byproduct harmful to the liver. With Lake Erie as the primary source of water for upwards of 11 million people, the prevalence of algal blooms’ and threat of liver toxins are concerning for citizens and have previously led to water avoidance advisories.

The study supports and explains the concern regarding the algal bloom toxicity during the summer.

LSA junior Emily Boswell, an Earth and Environmental Science major, noted the importance of research done on Lake Erie’s algal blooms.

“Without research on the topic, it would be impossible to figure out all of the causes of the blooms and the potential ways to stop or at least manage the blooms,” Boswell said. “It’s reassuring to know that scientists at U of M are paying attention to (habitual algal blooms) and trying to find solutions to all of the problems that don’t necessarily affect them.”